Colorectal Cancer (i.e., cancer of the Colon, Rectum, Anus, Appendix) is the second leading cause of cancer deaths in the United States. Only lung cancer claims more lives. This year, more than 130,000 Americans will be diagnosed with colorectal cancer. Similar statistics are reported for many European countries. Certain types of cancer are associated with antigen markers in the blood, which holds a potential for early diagnosis by detection or monitoring of antigen levels. Examples of cancers and their associate antigen markers are: prostate cancer—PSA; pancreatic cancer—CA125; ovarian and uterine cancer—fetaprotein; breast and lung cancer—βdlh.
While cancer is generally more receptive to treatment if diagnosed in the early stages, it can be difficult to detect in an early stage. With the recent emergence of genetic expression profiling, oncologist have broken down malignancies to their genetic profile which will allow them to classify cancers into distinct categories. Tissues sampled for such genetic expression profiling can be studied for antigen markers associated with additional types of cancers.
Existing methods of detecting and monitoring cancer are time consuming and complex. For example, a patient must go to a facility, such as his physician's office, to have blood drawn. The blood is then sent to an on-site or off-site laboratory for processing to determine amounts of antigen markers. Costly equipment is generally required, and the overall process can take a great deal of time. The time-consuming nature of this process becomes particularly burdensome when a patient may return for testing periodically, such as weekly or monthly. Further, the invasive nature of blood tests is often a deterrent to patients.
A “biomaterial” is a non-living material used in a medical device which is intended to interact with biological systems. Such materials may be relatively “bioinert”, “biocompatible”, “bioactive” or “uresorbable”, depending on their biological response in vivo.
When silicon is deliberately riddled with nanometer-sized holes, it becomes biocompatible and biodegradable, and will not be rejected by the body and it will dissolve harmlessly over time. Silicon chips have been implanted into the body before—for example in cochlear implants that convert sounds into electrical signals and feed them directly into the brain—but they had to be shielded from body tissues and the bloodstream.
Porous silicon, or “Biosilicon™”, needs no such protection—its only by-product is silicic acid, which is present in many common foods and drinks. It can be crafted into orthopedic and electronic structures and perform a variety of medical functions inside the body automatically.
A Biosilicon implant could be crafted into temporary scaffolds or pins that would promote bone healing and growth and then dissolve into nothing. Alternatively, it could contain both a reservoir of drugs and a tiny computer system to control timing and dosage. It could even be used as an internal diagnostic device, transmitting data about a patient through his or her skin and enabling a doctor to fine-tune its drug-release program without the need for surgery.